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Posted: 12/1/2006 6:45:02 AM EDT
| I have been having problems with case ruptures in my AR. The rupture is a few millimeters in length a few millimeters down from the top of the cartridge, where the case necks down. My AR is a DPMS gun that I have built up. I put the lower together myself, but I ordered the upper/barrel assembly straight from DPMS already assembled. Out of a test firing of 60 rounds, it did this 3 times with Winchester .223 Rem 55 gr. and once with Sellier and Bellot .223 55 gr. My rifle is chambered in 5.56mm. I initially thought that it was a headspace issue so I contacted DPMS and sent the upper back in to them. They say that the headspace is correct and they ran 50 rounds of federal/American Eagle 55 gr. through the gun without a problem. They said that the failed casings that I sent them were out of spec, but I have never had problems with winchester or S&B ammo before. Has anyone seen anything like this? Is this an ammo problem or is there something else that could be wrong with the gun? |
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Headspace and chamber cross wall dimensions are not the same, but if DPMS did check the chamber, just caulk the problem up to brass that is too brittle, and cracking all by it’s self unless this is happening with brass all the way across the board (no matter what brass/ammo is being used). P.S. Welcome to the site!!! |
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